Class: Lllibrary::Playlist

Inherits:
ActiveRecord::Base
  • Object
show all
Defined in:
lib/lllibrary/playlist.rb

Overview

A Playlist is a list of Tracks in a particular order and with possible repeats of Tracks. A Playlist has a name, and that’s about it.

Instance Method Summary collapse

Instance Method Details

#add(track_or_tracks, at = nil) ⇒ Object

Adds the given Track or Array of Tracks to the end of the Playlist. If an index is given, the track(s) are inserted at that position.



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# File 'lib/lllibrary/playlist.rb', line 10

def add(track_or_tracks, at = nil)
  base_position = nil
  if at
    at_track = playlist_items.offset(at).first
    base_position = at_track.position if at_track
  end
  base_position ||= empty? ? 0 : playlist_items.last.position + 1

  playlist_items.where("playlist_items.position >= ?", base_position).update_all("position = position + #{Array(track_or_tracks).length}")

  Array(track_or_tracks).each.with_index do |track, i|
    playlist_item = Lllibrary::PlaylistItem.new
    playlist_item.track = track
    playlist_item.playlist = self
    playlist_item.position = base_position + i
    playlist_item.save!
  end

  reload
end

#clear ⇒ Object

Clears the playlist and saves.



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# File 'lib/lllibrary/playlist.rb', line 82

def clear
  playlist_items.destroy_all
  reload
end

#empty? ⇒ Boolean

Returns true if the playlist is empty.

Returns:

  • (Boolean) 


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# File 'lib/lllibrary/playlist.rb', line 45

def empty?
  playlist_items.empty?
end

#length ⇒ Object

Gets the number of items in the playlist.



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# File 'lib/lllibrary/playlist.rb', line 50

def length
  playlist_items.count
end

#remove(track_or_tracks) ⇒ Object

Removes the Track or Array of Tracks from the Playlist.



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# File 'lib/lllibrary/playlist.rb', line 32

def remove(track_or_tracks)
  playlist_items.where(track_id: track_or_tracks).destroy_all
  reload
end

#remove_at(index, n = 1) ⇒ Object

Removes the Track at the given index. If a number is given in the second argument, removes that number of tracks starting from index.



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# File 'lib/lllibrary/playlist.rb', line 39

def remove_at(index, n = 1)
  playlist_items.offset(index).limit(n).all.each(&:destroy)
  reload
end

#shuffle ⇒ Object

Shuffles the playlist and saves.



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# File 'lib/lllibrary/playlist.rb', line 75

def shuffle
  shuffled_tracks = tracks.shuffle
  clear
  add(shuffled_tracks)
end

#sort(&blk) ⇒ Object

Sorts the playlist using the given block, then saves. See Array#sort.



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# File 'lib/lllibrary/playlist.rb', line 68

def sort(&blk)
  sorted_tracks = tracks.sort(&blk)
  clear
  add(sorted_tracks)
end

#total_length(options = {}) ⇒ Object

Calculates the total length of the playlist by summing the tracks’ total_time column by default, which stores milliseconds by default. You can provide a different column using the :field option, like so:

playlist.total_length(field: :length)

If the given field stores time in milliseconds, this method returns milliseconds. If it stores time in seconds, this returns seconds. And so on.



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# File 'lib/lllibrary/playlist.rb', line 63

def total_length(options = {})
  tracks.sum(options[:field] || :total_time)
end